pscontour - Contour xyz-data by direct triangulation
pscontour xyzfile -Ccptfile -Jparameters -Rwest/east/south/north[r] [
-A[-][labelinfo] ] [ -Btickinfo ] [ -D[dumpfile] ] [ -Eview_az/view_el
] [ -G[d|f|n|l|L|x|X]info ] [ -H[nrec] ] [ -I ] [ -K ] [ -Lpen ] [
-M[flag] ] [ -N ] [ -O ] [ -P ] [ -S ] [ -Tindexfile ] [
-U[/dx/dy/][label] ] [ -V ] [ -W[+]pen ] [ -Xx-shift ] [ -Yy-shift ] [
-ccopies ] [ -: ] [ -bi[s][n] ] [ -bo[s][n] ]
pscontour reads an ASCII [or binary] xyz-file and produces a raw con-
tour plot by triangulation. By default, the optimal Delaunay triangula-
tion is performed (using either Shewchuk’s  or Watson’s 
method as selected during GMT installation), but the user may option-
ally provide a second file with network information, such as a triangu-
lar mesh used for finite element modeling. In addition to contours, the
area between contours may be painted according to the color palette
Raw ASCII (or binary, see -b) xyz data to be contoured.
-C name of the color palette file. Must have discrete colors if you
want to paint the surface (-I). Only contours that have annota-
tion flags set will be annotated.
-J Selects the map projection. Scale is UNIT/degree, 1:xxxxx, or
width in UNIT (upper case modifier). UNIT is cm, inch, or m,
depending on the MEASURE_UNIT setting in .gmtdefaults4, but this
can be overridden on the command line by appending c, i, or m to
the scale/width value. For map height, max dimension, or min
dimension, append h, +, or - to the width, respectively.
-Jmscale (Mercator - Greenwich and Equator as origin)
-Jmlon0/lat0/scale (Mercator - Give meridian and standard paral-
-Joalon0/lat0/azimuth/scale (Oblique Mercator - point and
-Joblon0/lat0/lon1/lat1/scale (Oblique Mercator - two points)
-Joclon0/lat0/lonp/latp/scale (Oblique Mercator - point and
-Jqlon0/scale (Equidistant Cylindrical Projection (Plate Car-
-Jtlon0/scale (TM - Transverse Mercator, with Equator as y = 0)
-Jtlon0/lat0/scale (TM - Transverse Mercator, set origin)
-Juzone/scale (UTM - Universal Transverse Mercator)
-Jylon0/lats/scale (Basic Cylindrical Projection)
-Jslon0/lat0/[slat/]scale (General Stereographic)
-Jk[f|s]lon0/scale (Eckert IV (f) and VI (s))
-Jrlon0/scale (Winkel Tripel)
-Jvlon0/scale (Van der Grinten)
-Jp[a]scale[/origin] (polar (theta,r) coordinates, optional a
for azimuths and offset theta )
-Jxx-scale[l|ppow][/y-scale[l|ppow]][d] (Linear, log, and power
More details can be found in the psbasemap man pages.
-R xmin, xmax, ymin, and ymax specify the Region of interest. For
geographic regions, these limits correspond to west, east,
south, and north and you may specify them in decimal degrees or
in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left
and upper right map coordinates are given instead of wesn. The
two shorthands -Rg -Rd stand for global domain (0/360 or
-180/+180 in longitude respectively, with -90/+90 in latitude).
For calendar time coordinates you may either give relative time
(relative to the selected TIME_EPOCH and in the selected
TIME_UNIT; append t to -JX|x), or absolute time of the form
[date]T[clock] (append T to -JX|x). At least one of date and
clock must be present; the T is always required. The date string
must be of the form [-]yyyy[-mm[-dd]] (Gregorian calendar) or
yyyy[-Www[-d]] (ISO week calendar), while the clock string must
be of the form hh:mm:ss[.xxx]. The use of delimiters and their
type and positions must be as indicated (however, input/output
and plotting formats are flexible).
No space between the option flag and the associated arguments.
-A Give - to disable all annotations. The optional labelinfo con-
trols the specifics of the label formatting and consists of a
concatenated string made up of any of the following control
+aangle for annotations at a fixed angle, +an for line-normal,
or +ap for line-parallel [Default].
+cdx[/dy] sets the clearance between label and optional text
box. Append c|i|m|p to specify the unit or % to indicate a per-
centage of the label font size [15%].
+ffont sets the desired font [Default ANNOT_FONT_PRIMARY].
+g[color] selects opaque text boxes [Default is transparent];
optionally specify the color [Default is PAGE_COLOR].
+jjust sets label justification [Default is CM].
+kcolor sets color of text labels [Default is COLOR_BACKGROUND].
+llabel sets the constant label text.
+Llflag sets the label text according to the specified flag:
flag is h: Take the label from the current multisegment header
(first scan for an embedded -Llabel option, if not use the first
word following the segment flag).
flag is d: Take the Cartesian plot distances along the line as
the label; append c|i|m|p as the unit [Default is MEASURE_UNIT].
flag is D: Calculate actual map distances; append d|e|k|m|n as
the unit [Default is d(egrees), unless label placement was based
on map distances along the lines in which case we use the same
unit specified for that algorithm]. Requires a map projection
to be used.
flag is f: Use text after the 2nd column in the fixed label
location file as the label. Requires the fixed label location
flag is x: As h but use the headers in the xfile.d instead.
Requires the crossing file option.
+o selects rounded rectangular text box [Default is rectangu-
lar]. Not applicable for curved text (+v) and only makes sense
for opaque text boxes.
+p[pen] draws the outline of text boxsets [Default is no out-
line]; optionally specify pen for outline [Default is width =
0.25p, color = black, texture = solid].
+rmin_rad will not place labels where the line’s radius of cur-
vature is less than min_rad [Default is 0].
+ssize sets the desired font size in points [Default is 9].
+uunit appends unit to all line labels. If unit starts with a
leading hypen (-) then there will be no space between label
value and the unit. [Default is no unit].
+v specifies curved labels following the path [Default is
+w specifies how many (x, y) points will be used to estimate
label angles [Default is 10].
+=prefix prepends prefix to all line labels. If prefix starts
with a leading hypen (-) then there will be no space between
label value and the prefix. [Default is no prefix].
-B Sets map boundary annotation and tickmark intervals; see the
psbasemap man page for all the details.
-D Dump the (x,y,z) coordinates of each contour to separate files,
one for each contour segment. The files will be named dump-
file_cont_segment[_i].xyz, where cont is the contour value and
segment is a running segment number for each contour interval
(for closed contours we append _i.) However, when -M is used in
conjunction with -D a single multisegment file is created
-E Sets the view point by specifying azimuth and elevation in
degrees. [Default is 180/90].
-G Controls the placement of labels along the contours. Choose
among five controlling algorithms:
-Gddist[c|i|m|p] or -GDdist[d|e|k|m|n]. For lower case d, give
distances between labels on the plot in your preferred measure-
ment unit c (cm), i (inch), m (meter), or p (points), while for
upper case D, specify distances in map units and append the
unit; choose among e (m), k (km), m (mile), n (nautical mile),
or d (spherical degree). [Default is 10c or 4i].
-Gfffile.d reads the ascii file ffile.d and places labels at
locations in the file that matches locations along the contours.
Inexact mathces and points outside the region are skipped.
-Gl|Lline1[,line2,...] Give start and stop coordinates for one
or more comma-separated straight line segments. Labels will be
placed where these lines intersect the contours. The format of
each line specification is start/stop, where start and stop are
either a specified point lon/lat or a 2-character XY key that
uses the justification format employed in pstext to indicate a
point on the map, given as [LCR][BMT]. -GL will interpret the
point pairs as defining great circles [Default is straight
-Gnn_label specifies the number of equidistant labels for con-
tours line . Upper case -GN starts labeling exactly at the
start of the line [Default centers them along the line]. -GN-1
places one justified label at start, while -GN+1 places one jus-
tified label at the end of contours. Optionally, append
/min_dist[c|i|m|p] to enforce that a minimum distance separation
between successive labels is enforced.
-Gx|Xxfile.d reads the multi-segment file xfile.d and places
labels at the intersections between the contours and the lines
inxfile.d. -GX will resample the lines first along great-circle
-H Input file(s) has Header record(s). Number of header records can
be changed by editing your .gmtdefaults4 file. If used, GMT
default is 1 header record. Use -Hi if only input data should
have header records [Default will write out header records if
the input data have them].
-I Color the triangles using the color palette table.
-K More PostScript code will be appended later [Default terminates
the plot system].
-L Draw the underlying triangular mesh using the specified pen
attributes [Default is no mesh].
-M When used in conjunction with -D a single multisegment file is
created, and each contour section is preceded by a header record
whose first column is flag followed by the contour level.
-N Do NOT clip contours or image at the boundaries [Default will
clip to fit inside region -R].
-O Selects Overlay plot mode [Default initializes a new plot sys-
-P Selects Portrait plotting mode [GMT Default is Landscape, see
gmtdefaults to change this].
-S Skip all input xyz points that fall outside the region [Default
uses all the data in the triangulation].
-T Give name of file with network information. Each record must
contain triplets of node numbers for a triangle [Default com-
putes these using Delaunay triangulation (see triangulate)].
-U Draw Unix System time stamp on plot. User may specify where the
lower left corner of the stamp should fall on the page relative
to lower left corner of plot. Optionally, append a label, or c
(which will plot the command string.). The GMT parameters
UNIX_TIME and UNIX_TIME_POS can affect the appearance; see the
gmtdefaults man page for details.
-V Selects verbose mode, which will send progress reports to stderr
[Default runs "silently"].
-W Select contouring and set contour pen attributes. If the + flag
is set then the contour lines are colored according to the cpt
file (see -C).
-X -Y Shift origin of plot by (x-shift,y-shift). Prepend a for abso-
lute coordinates; the default (r) will reset plot origin. Give
c to center plot using current page size.
-c Specifies the number of plot copies. [Default is 1].
-: Toggles between (longitude,latitude) and (latitude,longitude)
input and/or output. [Default is (longitude,latitude)]. Append
i to select input only or o to select output only. [Default
-bi Selects binary input. Append s for single precision [Default is
double]. Append n for the number of columns in the binary
[Default is 3 input columns]. Use 4-byte integer triplets for
node ids (-T).
-bo Selects binary output. Append s for single precision [Default is
double]. Append n for the number of columns in the binary
To make a raw contour plot from the file topo.xyz and drawing the con-
tours (pen = 2) given in the color palette file topo.cpt on a Lambert
map at 0.5 inch/degree along the standard parallels 18 and 24, use
pscontour topo.xyz -R320/330/20/30 -Jl18/24/0.5i -Ctopo.cpt -W0.5p >
To create a color PostScript plot of the numerical temperature solution
obtained on a triangular mesh whose node coordinates and temperatures
are stored in temp.xyz and mesh arrangement is given by the file
mesh.ijk, using the colors in temp.cpt, run
pscontour temp.xyz -R0/150/0/100 -Jx0.1 -Ctemp.cpt -G -W0.25p > temp.ps
Sometimes there will appear to be thin lines of the wrong color in the
image. This is a round-off problem which may be remedied by using a
higher value of DOTS_PR_INCH in the .gmtdefaults4 file.
gmt(l), grdcontour(l), grdimage(l), nearneighbor(l), psbasemap(l), pss-
cale(l), surface(l), triangulate(l)
Watson, D. F., 1982, Acord: Automatic contouring of raw data, Comp. &
Geosci., 8, 97-101.
Shewchuk, J. R., 1996, Triangle: Engineering a 2D Quality Mesh Genera-
tor and Delaunay Triangulator, First Workshop on Applied Computational
Geometry (Philadelphia, PA), 124-133, ACM, May 1996.
GMT4.0 1 Oct 2004 PSCONTOUR(l)
Man(1) output converted with